Cardiac monitoring and cardiovascular event incidence in patients over 50 with ICU needs undergoing abdominal/vascular surgery: Insights from a tertiary care facility

Abstract

Background

As the global population ages, the vulnerability of older adults (≥50 years) undergoing major non-cardiac surgeries increases significantly, posing greater risks and challenges. This study aims to address the gap in understanding postoperative cardiac complications and associated risk factors in this demographic.

Methods

A retrospective observational study was conducted to identify 100 patients aged 50 or older who underwent major abdominal or vascular surgeries requiring ICU admission for more than 24 h. MACE incidence, including myocardial infarction, unstable angina, heart failure, arrhythmias, stroke, and cardiac death, was assessed. Logistic regression analyzed preoperative risk factors.

Results

Postoperatively, 18 % experienced MACE events, including acute coronary syndrome, unstable angina, and cardiac death. Vascular surgeries correlated with increased mortality risk ( p < 0.001). Hypertension emerged as a significant risk factor (OR 10.88, p < 0.02), alongside abnormal echocardiogram findings ( p < 0.05).

Discussion

The study highlights the significant association of advanced age, hypertension, and echocardiographic abnormalities with MACE in elderly patients undergoing major abdominal/vascular surgeries requiring ICU care. The findings emphasize the importance of perioperative risk stratification, particularly in high-risk groups, to guide surgical planning and improve outcomes. Developing predictive tools, such as MACE risk calculators, could support clinical decision-making.

Conclusion

Age, hypertension, and echocardiographic findings are key MACE predictors in elderly surgical patients requiring ICU care. Future studies should focus on validating risk calculators and optimizing perioperative strategies to improve patient outcomes.

Introduction

Patients aged over 50 years are often classified as older adults, and they exhibit increased vulnerability and risk prior to major non-cardiac surgeries compared to younger individuals, primarily due to factors such as aging, diminished functional capacity, and underlying comorbidities. This heightened vulnerability is associated with a greater likelihood of experiencing cognitive impairments, reduced cardiac, pulmonary, and renal function, elevated mortality rates, stroke, delirium, neurological complications, physical inactivity, and the presence of multiple comorbidities.

The number of older adults undergoing surgical interventions has been steadily rising each year and is expected to continue increasing as the population ages. Managing the perioperative care of older patients poses a significant challenge for healthcare providers, as it differs markedly from managing younger individuals. Older patients typically present with pathophysiological factors that predispose them to perioperative complications, prolonged hospital stays, and an increased risk of iatrogenesis, nosocomial infections, and perioperative mortality.

Major adverse cardiac events (MACEs) encompass a spectrum of cardiovascular events necessitating re-hospitalization for cardiovascular-related conditions. These events include myocardial infarction, arrhythmias, heart failure, coronary artery disease, ventricular tachycardia or fibrillation, stroke, peripheral revascularization, unstable angina, heart failure, cardiogenic shock, and cardiac death. Assessing these cardiovascular events can be challenging and is associated with elevated morbidity and mortality rates.

India witnesses approximately 3 million surgeries annually. Older patients aged 50 and above face a heightened risk of diminished cardiac, pulmonary, and renal function, as well as physical and cognitive impairments, and multiple comorbidities during their hospital stay. Notably, older patients undergoing major non-cardiac surgeries, such as abdominal or vascular surgeries, are particularly susceptible to cardiovascular events and associated mortality and morbidity during both the perioperative and recovery phases.

Despite the significant risk posed, postoperative cardiac complications in this patient demographic have received limited attention in terms of understanding cardiovascular incidence and associated risk factors. To bridge this gap in knowledge, a retrospective study was undertaken to identify variables associated with an increased risk of cardiac complications. The primary objective was to determine the incidence of MACE following major non-cardiac surgeries, such as abdominal or vascular surgeries, during hospitalization until discharge, and to correlate these events with preoperative risk stratification and postoperative care.

Subjects and methods

A retrospective observational study was conducted at Narayana Institute of Cardiac Sciences, Bengaluru, India, after obtaining approval from the Institutional Ethics Committee (NHH/AEC-CL-2020–604). As this was a retrospective study, a waiver of consent was sought, and data were collected in an anonymized manner from the Medical Records Department (MRD) for immediate postoperative MACE during the period of 2020–2021. The study was conducted and has been reported in accordance with the STROBE guidelines for observational studies.

The study included all eligible participants: 1. aged 50 or older, 2. who underwent major non-cardiac surgeries (abdominal or vascular surgeries), encompassing both elective and emergency cases, and 3. required intensive care unit admission for more than 24 h. This inclusion criterion ensures the study focuses on patients with significant perioperative care needs requiring close monitoring and specialized support. Patients meeting any of the following criteria were excluded: 1. those with missing data, 2. those scheduled for same-day admission and discharge, or 3. those who received local or peripheral nerve anesthesia. This exclusion criterion was essential to ensure the inclusion of only patients meeting the defined criteria and to uphold the internal validity of the study.

The study outcome was defined to include several MACE, including myocardial infarction, unstable angina, congestive heart failure, atrial fibrillation, ventricular arrhythmia, coronary artery disease, stroke, and cardiac death. This study was conducted in accordance with the ethical standards of the responsible institution regarding human subjects, as well as in compliance with the principles outlined in the Helsinki Declaration.

Statistical methods

The sample size was calculated based on an expected prevalence of MACE of 10 % among patients aged over 45 years undergoing non-cardiac surgery, with a precision of 5 %. The study aimed for a 99 % confidence interval to detect at least 24 cases of major vascular events occurring from hospital admission to discharge after surgery, resulting in an estimated sample size of 239.

Data were analysed using SPSS software version 21. Baseline characteristics were described using descriptive statistics. Continuous variables were expressed as mean and standard deviation, while categorical variables were presented as frequency and percentage. Logistic regression was employed to investigate pre-operative risk factors associated with the development of MACE. A p-value less than 0.05 was considered statistically significant.

Results

The study analysed data from 100 patients. Table 1 compares the baseline characteristics of patients with and without MACE events. The mean age was 62.5 years, and 66 (66 %) were males. The mean BMI was 27 kg/m². The percentage of patients with a history of smoking and alcohol consumption were 13 (13.0 %) and 7 (7.0 %) respectively. 82 % of the patients had undergone abdominal surgery; however, the incidence of MACE occurred equally in patients undergoing abdominal surgery and vascular surgery.

Table 1

Comparison of Baseline Characteristics of patients with and without MACE events.

	Descriptive Statistics ( N = 100)	Presence of MACE Event ( n = 18)	Absence of MACE Event ( n = 82)	p-value
Age (year) [Mean ± SD]	62.47 ± 9.0	61.72 ± 8.3	62.63 ± 9.2	0.70
Male [n, %]	66 (66.0 %)	16 (88.9 %)	50 (61.0 %)	0.03
Height (cm) [Mean ± SD]	160.90 ± 9.8	160.67 ± 9.6	160.95 ± 9.9	0.91
Weight (kg) [Median (Q3-Q1)]	68.0 (74.0 – 62.0)	68.0 (72.5 – 64.7)	68.0 (74.2 – 61.7)	0.92
BMI (kg/m ²⁾Median [Q3-Q1]	27.0 [28.0 – 24.0]	27.0 [28.0 – 24.0]	27.0 [29.0 – 24.0]	0.89
Smoking (n, %)	13 (13.0 %)	4 (22.2 %)	9 (11.0 %)	0.24
Alcohol (n, %)	7 (7.0 %)	2 (11.1 %)	5 (6.1 %)	0.61
Surgery Type (n, %)
Elective	83 (83.0 %)	13 (72.2 %)	70 (85.4 %)
Emergency	17 (17.0 %)	5 (27.8 %)	12 (14.6 %)	0.16
Proposed Surgery (n, %)
Vascular Surgery (Total)	18 (18.0 %)	9 (50.0 %)	9 (11.0 %)
a. Carotid artery surgery	1 (1.0 %)
b. Endovascular aneurysm repair	3 (3.0 %)
c. Others	14 (14.0 %)
Abdominal Surgery (Total)	82 (82.0 %)	9 (50.0 %)	73 (89.0 %)	0.001
a. Appendicectomy	5 (5.0 %)
b. Cholecystectomy	30 (30.0 %)
c. Hernia	14 (14.0 %)
d. Others	33 (33.0 %)